/* =============拆分的split操作============ */
let str1 = '李白,杜甫'
let arr1 = str1.split(',')
// console.log('字符串split:',arr1)


/* =============拼接的join操作============ */
let arr2 = [ '李白', '杜甫' ]
let str2 = arr2.join(',')
// console.log('数组的join:',str2)


/* =============合并的concat操作============ */
// 不会改变原数组
let arr3 = [ '李白', '杜甫' ]
let temp3 = ['新增1']
arr3 = arr3.concat(temp3)
// console.log('数组的concat:',arr3)


/* =============合并的扩展操作============ */

let arr4 = [ '李白', '杜甫' ]
let temp4 = ['新增1']
arr4 = [...arr4,...temp4]
// console.log('数组的扩展:',arr4)